Radio receivers
US8249535B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 20, 2009 |
| Grant date | Aug 21, 2012 |
| Priority date | — |
| Expiry date | Oct 28, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03G3/3068
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A radio receiver comprises an input (14) for a modulated radio frequency signal, a frequency down converter (16) coupled to the input, the frequency down converter including quadrature mixers (32,34) for demodulating a received modulated radio frequency signal using a local oscillator signal. An analogue-to-digital converter (54, 56) is coupled to receive demodulated signals from the mixing means. The analogue-to-digital converter, which may comprise a continuous time sigma delta converter, has an input for a sampling clock frequency (f s). A voltage controlled oscillator (38) provides the local oscillator signal and supplies a frequency divider (60, 94) used to provide the sampling clock frequency. The dividing ratio (1/A) of the frequency divider is variable in response to variations in the strength of an 15 output signal from the digital-to-frequency converter and the variations in the frequency of the sampling clock frequency vary the gain of the analogue-to-frequency converter thereby providing automatic gain control.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.